Improve efficiency of Java implementation of natives.

native/build.gradle

@@ -8,7 +8,7 @@ apply from: '../gradle/checkstyle.gradle'
 
 dependencies {
     compile "com.google.guava:guava:${guavaVersion}"
-    compile "io.netty:netty-buffer:${nettyVersion}"
+    compile "io.netty:netty-handler:${nettyVersion}"
     compile "org.checkerframework:checker-qual:${checkerFrameworkVersion}"
 
     testCompile "org.junit.jupiter:junit-jupiter-api:${junitVersion}"

native/src/main/java/com/velocitypowered/natives/encryption/JavaVelocityCipher.java

@@ -2,6 +2,7 @@ package com.velocitypowered.natives.encryption;
 
 import com.google.common.base.Preconditions;
 import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
 import java.security.GeneralSecurityException;
 import javax.crypto.Cipher;
 import javax.crypto.SecretKey;
@@ -21,6 +22,9 @@ public class JavaVelocityCipher implements VelocityCipher {
       return new JavaVelocityCipher(false, key);
     }
   };
+  private static final int INITIAL_BUFFER_SIZE = 1024 * 16;
+  private static final ThreadLocal<byte[]> inBufLocal = ThreadLocal.withInitial(
+      () -> new byte[INITIAL_BUFFER_SIZE]);
 
   private final Cipher cipher;
   private boolean disposed = false;
@@ -35,13 +39,36 @@ public class JavaVelocityCipher implements VelocityCipher {
   public void process(ByteBuf source, ByteBuf destination) throws ShortBufferException {
     ensureNotDisposed();
 
-    byte[] sourceAsBytes = new byte[source.readableBytes()];
-    source.readBytes(sourceAsBytes);
+    int inBytes = source.readableBytes();
+    byte[] inBuf = slurp(source);
 
-    int outputSize = cipher.getOutputSize(sourceAsBytes.length);
-    byte[] destinationBytes = new byte[outputSize];
-    cipher.update(sourceAsBytes, 0, sourceAsBytes.length, destinationBytes);
-    destination.writeBytes(destinationBytes);
+    int outputSize = cipher.getOutputSize(inBytes);
+    byte[] outBuf = new byte[outputSize];
+    cipher.update(inBuf, 0, inBytes, outBuf);
+    destination.writeBytes(outBuf);
+  }
+
+  @Override
+  public ByteBuf process(ChannelHandlerContext ctx, ByteBuf source) throws ShortBufferException {
+    ensureNotDisposed();
+
+    int inBytes = source.readableBytes();
+    byte[] inBuf = slurp(source);
+
+    ByteBuf out = ctx.alloc().heapBuffer(cipher.getOutputSize(inBytes));
+    out.writerIndex(cipher.update(inBuf, 0, inBytes, out.array(), out.arrayOffset()));
+    return out;
+  }
+
+  private static byte[] slurp(ByteBuf source) {
+    int inBytes = source.readableBytes();
+    byte[] inBuf = inBufLocal.get();
+    if (inBuf.length <= inBytes) {
+      inBuf = new byte[inBytes];
+      inBufLocal.set(inBuf);
+    }
+    source.readBytes(inBuf, 0, inBytes);
+    return inBuf;
   }
 
   @Override

native/src/main/java/com/velocitypowered/natives/encryption/NativeVelocityCipher.java

@@ -1,6 +1,7 @@
 package com.velocitypowered.natives.encryption;
 
 import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
 import java.security.GeneralSecurityException;
 import javax.crypto.SecretKey;
 import javax.crypto.ShortBufferException;
@@ -45,6 +46,18 @@ public class NativeVelocityCipher implements VelocityCipher {
     destination.writerIndex(destination.writerIndex() + len);
   }
 
+  @Override
+  public ByteBuf process(ChannelHandlerContext ctx, ByteBuf source) throws ShortBufferException {
+    ByteBuf out = ctx.alloc().directBuffer(source.readableBytes());
+    try {
+      process(source, out);
+      return out;
+    } catch (Exception e) {
+      out.release();
+      throw e;
+    }
+  }
+
   @Override
   public void dispose() {
     if (!disposed) {

native/src/main/java/com/velocitypowered/natives/encryption/VelocityCipher.java

@@ -2,9 +2,12 @@ package com.velocitypowered.natives.encryption;
 
 import com.velocitypowered.natives.Disposable;
 import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
 import javax.crypto.ShortBufferException;
 
 public interface VelocityCipher extends Disposable {
 
   void process(ByteBuf source, ByteBuf destination) throws ShortBufferException;
+
+  ByteBuf process(ChannelHandlerContext ctx, ByteBuf source) throws ShortBufferException;
 }

native/src/main/java/com/velocitypowered/natives/util/NativeCodeLoader.java

@@ -75,11 +75,5 @@ public final class NativeCodeLoader<T> implements Supplier<T> {
     SETUP_FAILURE
   }
 
-  static final BooleanSupplier MACOS = () ->
-      System.getProperty("os.name", "").equalsIgnoreCase("Mac OS X")
-          && System.getProperty("os.arch").equals("x86_64");
-  static final BooleanSupplier LINUX = () ->
-      System.getProperties().getProperty("os.name", "").equalsIgnoreCase("Linux")
-          && System.getProperty("os.arch").equals("amd64");
   static final BooleanSupplier ALWAYS = () -> true;
 }

native/src/main/java/com/velocitypowered/natives/util/NativeConstraints.java

@@ -0,0 +1,19 @@
+package com.velocitypowered.natives.util;
+
+import java.util.function.BooleanSupplier;
+
+public class NativeConstraints {
+  private static final boolean NATIVES_ENABLED = !Boolean.getBoolean("velocity.natives-disabled");
+
+  static final BooleanSupplier MACOS = () -> {
+    return NATIVES_ENABLED
+        && System.getProperty("os.name", "").equalsIgnoreCase("Mac OS X")
+        && System.getProperty("os.arch").equals("x86_64");
+  };
+
+  static final BooleanSupplier LINUX = () -> {
+    return NATIVES_ENABLED
+        && System.getProperty("os.name", "").equalsIgnoreCase("Linux")
+        && System.getProperty("os.arch").equals("amd64");
+  };
+}

native/src/main/java/com/velocitypowered/natives/util/Natives.java

@@ -46,10 +46,10 @@ public class Natives {
 
   public static final NativeCodeLoader<VelocityCompressorFactory> compress = new NativeCodeLoader<>(
       ImmutableList.of(
-          new NativeCodeLoader.Variant<>(NativeCodeLoader.MACOS,
+          new NativeCodeLoader.Variant<>(NativeConstraints.MACOS,
               copyAndLoadNative("/macosx/velocity-compress.dylib"), "native (macOS)",
               NativeVelocityCompressor.FACTORY),
-          new NativeCodeLoader.Variant<>(NativeCodeLoader.LINUX,
+          new NativeCodeLoader.Variant<>(NativeConstraints.LINUX,
               copyAndLoadNative("/linux_x64/velocity-compress.so"), "native (Linux amd64)",
               NativeVelocityCompressor.FACTORY),
           new NativeCodeLoader.Variant<>(NativeCodeLoader.ALWAYS, () -> {
@@ -59,10 +59,10 @@ public class Natives {
 
   public static final NativeCodeLoader<VelocityCipherFactory> cipher = new NativeCodeLoader<>(
       ImmutableList.of(
-          new NativeCodeLoader.Variant<>(NativeCodeLoader.MACOS,
+          new NativeCodeLoader.Variant<>(NativeConstraints.MACOS,
               copyAndLoadNative("/macosx/velocity-cipher.dylib"), "mbed TLS (macOS)",
               NativeVelocityCipher.FACTORY),
-            new NativeCodeLoader.Variant<>(NativeCodeLoader.LINUX,
+            new NativeCodeLoader.Variant<>(NativeConstraints.LINUX,
               copyAndLoadNative("/linux_x64/velocity-cipher.so"), "mbed TLS (Linux amd64)",
               NativeVelocityCipher.FACTORY),
           new NativeCodeLoader.Variant<>(NativeCodeLoader.ALWAYS, () -> {

proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftCipherDecoder.java

@@ -17,14 +17,7 @@ public class MinecraftCipherDecoder extends ByteToMessageDecoder {
 
   @Override
   protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
-    ByteBuf decrypted = ctx.alloc().buffer(in.readableBytes());
-    try {
-      cipher.process(in, decrypted);
-      out.add(decrypted);
-    } catch (Exception e) {
-      decrypted.release();
-      throw e;
-    }
+    out.add(cipher.process(ctx, in));
   }
 
   @Override